Features: Engages kids in interactive mathematics operations practice with this innovative rolling stamp that ensures endless addition and subtraction problems through simple wheel rotation. Crafted from ABS plastic with number roller wheel, this refillable roller stamp combines safety and functionality for repeated learning. Designed for parent, teachers, and students aged 5-12 seeks engaging mathematics practice tool for home or classroom environments. Effortlessly create mathematics operations worksheets during homework time, tutoring, or nighttime study. Streamlines math drills while sparking curiosity – the compact stamp stores inks internally and cleans easily, making it reusable learning aid for years. Specifications: Component: ABS Plastic Color: White Stamper Size: Approx. 5x7cm/1.96x2.76in Weight: Approx. 60g Package Includes: 1Piece Mathematics Addition And Subtraction Roller Stamp with Refill Inks note: 1.Please allow 0-1cm error due to manual measurement. Be sure you donot mind before bid. 2.Due to difference between different monitors, the picture may not reflect the actual color